DESCRIPTION (Applicant's abstract): This project will compare the stereoscopic mechanisms in human vision which process disparity for the perception of depth to those which control horizontal eye vergence, in order to attain an integrated understanding of sensory and motor processing of retinal disparity. The knowledge gained will lead eventually to the treatment of binocular visual disorders. A model for the processing of static disparity in dynamic random-dot stereograms is developed based on previous psychophysical experiments. The model describes the stimulus to disparity processing mechanisms as the cross-correlation product of edge information in spatially-filtered left and right retinal images. The model further proposes a set of disparity-tuned interocular correlation detectors whose tuning widths increase and whose sensitivities decrease with disparity. Proposed experiments test this model with regard to the processing of disparity in dynamic random-dot stereograms for the control of vergence eye movements. The accuracy of continuous sinusoidal vergence tracking is measured as a function of the interocular correlation and luminance contrast of the stereogram stimuli, to assess the validity of the model's definition of signal strength with respect to vergence. The amplitude and latency of step vergence responses is measured under conditions of adaptation which are known to desensitize disparity-tuned channels, to assess the applicability of the model's channel descriptions with respect to vergence.